Henrique,
That works great! Thanks. The row3 is a sequence that restarts each time a new row2 is reached. Row4 is a sequence that restarts each time a new row2 is reached OR row1 reaches some threshold. By setting a threshold of 3, we expect a restart of the sequence once row1 reaches 3. This way we can have two unique sequences for each row2, assuming of course the threshold is reached. Jason ________________________________ From: Henrique Dallazuanna [mailto:www...@gmail.com] Sent: Thursday, August 27, 2009 11:02 AM To: Jason Baucom Cc: r-help@r-project.org; Steven Few Subject: Re: [R] generating multiple sequences in subsets of data Try this; stuff$row3 <- with(stuff, ave(row1, row2, FUN = seq)) I don't understand the fourth column On Thu, Aug 27, 2009 at 11:55 AM, Jason Baucom <jason.bau...@ateb.com> wrote: I'm running into a problem I can't seem to find a solution for. I'm attempting to add sequences into an existing data set based on subsets of the data. I've done this using a for loop with a small subset of data, but attempting the same process using real data (200k rows) is taking way too long. Here is some sample data and my ultimate goal > row1<-c(0,1,2,3,4,5,1,2,3,4) > row2<-c(1,1,1,1,1,1,2,2,2,2) > stuff<-data.frame(row1=row1,row2=row2) > stuff row1 row2 1 0 1 2 1 1 3 2 1 4 3 1 5 4 1 6 5 1 7 1 2 8 2 2 9 3 2 10 4 2 I need to derive 2 columns. I need a sequence for each unique row2, and then I need a sequence that restarts based on a cutoff value for row1 and unique row2. The following table is what is -should- look like using a cutoff of 3 for row4 row1 row2 row3 row4 1 0 1 1 1 2 1 1 2 2 3 2 1 3 3 4 3 1 4 1 5 4 1 5 2 6 5 1 6 3 7 1 2 1 1 8 2 2 2 2 9 3 2 3 1 10 4 2 4 2 I need something like row3<-sequence(nrow(unique(stuff$row2))) that actually works :-) Here is the for loop that functions properly for row3: stuff$row3<-c(1) for (i in 2:nrow(stuff)) { if ( stuff$row2[i] == stuff$row2[i-1]) { stuff$row3[i] = stuff$row3[i-1]+1}} Thanks! Jason Baucom Ateb, Inc. 919.882.4992 O 919.872.1645 F www.ateb.com <http://www.ateb.com/> [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O [[alternative HTML version deleted]]
______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.